Prevalence, antimicrobial resistance, and molecular characterization of Campylobacter jejuni and C. coli isolated from retail raw meat in Poland

The study was conducted to investigate the presence of Campylobacter spp. in meat sold to consumers at a retail market in Poland. Antimicrobial resistance and the presence of putative virulence genes of the isolates were also examined. A total of 558 meat samples, including beef (n = 105), pork (n = 85), and poultry (n = 368) were collected over an almost three year study period. It was found that 321 samples, all of them originating from poultry, were contaminated with Campylobacter spp. Most of the obtained isolates were classified as C. coli (189 strains, 58.9%), whereas C. jejuni was identified in 132 (41.1%) samples. All Campylobacter strains were susceptible to gentamicin and all but one C. coli isolate to erythromycin. On the other hand, the highest level of resistance among Campylobacter tested was to ciprofloxacin (91% for C. jejuni and 86.1% for C. coli) and nalidixic acid (89.3% for C. jejuni and 85% for C. coli). Furthermore, resistance to two or more classes of antibiotics was found in the majority (60.9%) of Campylobacter spp. and among them one C. coli strain showed resistance to four different classes of antimicrobials. Identification of virulence genes in the isolated Campylobacter showed that all of them had the flaA and cadF genes. The iam marker was found more often in C. coli strains (88.8%) compared to C. jejuni isolates (53.8%). On the other hand, the virB11 gene was identified only in 4.2% of C. coli and in 6.1% of C. jejuni strains, respectively. Furthermore, the prevalence of the cdtA, cdtB, and cdtC genes among C. jejuni strains was 97.7%, 93.2%, 96.2%, respectively, and was significantly higher than for C. coli regarding the cdtC (66.7%) gene. The obtained results showed that the presence of Campylobacter in retail meat may represent a threat to public health.